1. Field of the Invention
The present invention relates to a circuit for remote-controlling an electromagnetic shutter release camera or a device capable of electromagnetically controlling the shutter release of a camera, such as a motor drive device.
2. Description of the Prior Art
There is already known a remote control system for a camera or a motor drive device therefor by a control switch unit connected to said camera or motor drive device through plural electric contacts. Such plural electric contacts are required, for example in a camera having an automatic exposure control system, for the two-step operation, wherein the first step is for energizing the electric circuits in the camera and displaying the exposure conditions and the second step is for releasing the shutter of the camera. Although such first step for displaying the exposure conditions is not necessarily required in remote control at a distance from the camera, such displaying function is still required in case the remote control is utilized for preventing mechanical vibration of the camera at the shutter release, for example in close-up photographing such as document copying or in photographing through a microscope. Consequently in the conventional remote control system there have been required two independent terminals for achieving the aforementioned first and second steps in addition to a common terminal. In the miniaturization of the camera or the motor drive device, if a connector is required for remote control it is desirable to have minimum number of terminals for a smaller space, a lower cost, a better design and a higher reliability of the electric contact.